Method and apparatus for intraluminally implanting an endovascular aortic graft

ABSTRACT

An intraluminal prosthesis for intraluminal repair of body conduits, especially aortic aneurysms, is disclosed. The prosthesis includes a generally tubular, flexible graft ( 20 ) having a proximal open end ( 30 ) and at least one distal open end ( 31 ) terminating in a hem ( 33 ). A stent ( 21 ) can be disposed within the proximal open end ( 30 ) and is adapted to be attached to the body conduit ( 1 ). The hem ( 33 ) is inverted within the graft so that it is disposed as a cuff ( 34 ) within the graft. The hem ( 33 ) is arranged so that upon withdrawing the distal open end ( 31 ) from inside the cuff ( 34 ), the cuff will unfold and follow the distal open end to expose it to receive another stent for attachment to the body conduit ( 12 ) for intraluminal implantation of the graft. Preferably the hem is folded a second time within the cuff to form a second cuff ( 35 ) within the graft. The stents are preferably formed of a plexus of wires adapted to expand from a first narrow diameter to a second diameter to engage the body conduit. Also disclosed is a method of intraluminal implantation of the graft.

FIELD OF THE INVENTION

[0001] The present invention relates to an interluminal prosthesis forintraluminal repair of body conduits. More specifically, the presentinvention relates to intraluminal repair of aneurysms using an arterialinterluminal prothesis. Furthermore, the present invention relates to amethod of implanting the interluminal prosthesis in an artery. Theinvention especially relates to an arterial interluminal prosthesishaving a tubular form where one end of the tube is connected to thethoracic aorta and the other end is bifurcated to form two tubularpassageways and each passageway is connectable to each of the iliacarteries.

DESCRIPTION OF THE PRIOR ART

[0002] Interluminal devices for repairing body conduits are well knownto the art. Such devices include tubular flexible grafts that areimplanted by the use of stents. Stents are a means of attachment ofintravascular prostheses.

[0003] With special reference to abdominal aortic aneurysms, suchaneurysms occur because of an abnormal dilation of the wall of the aortawithin the abdomen. Surgical procedures involving the abdominal wall aremajor undertakings with high associated risk together with considerablemortality. The replacement of the aorta with surgical proceduresinvolves replacing the diseased portion of the vessel with a prostheticdevice which is typically formed of a synthetic tube or graft, usuallyfabricated of Dacron®, Teflon®, or other suitable material. In thesurgical procedure, the aorta is exposed through an abdominal incision.The aorta is closed both above and below the aneurysm so that theaneurysm can be opened and any thrombus and arteriosclerotic debris canbe removed. A graft of approximately the size of a normal aorta and issutured in place to replace the aneurysm. Blood flow is thenreestablished through the graft. Surgery according to the prior artrequired an extended recovery period together with difficulties insuturing the graft to the aorta.

[0004] In the European patent application to Barone et al., number0,461,791 A1, a method is disclosed for repairing an abdominal aorticaneurysm which includes a tubular graft that is intraluminally deliveredthrough the iliac artery and secured to the aorta by the expansion anddeformation of a stent. In the application, a tube is disclosed whichhas a single end that is bifurcated to two other ends each of which isattached to one of the iliac arteries. Such disposition of the graft canprovide a reduction in the trauma of the surgery because the graft isdelivered to the site intraluminally. While one connection to an iliacartery is reasonably easy to accomplish, rather complicated techniquesare required to move the other leg of the graft to the other iliacartery and connect it thereto.

[0005] A patent to Parodi et al., U.S. Pat. No. 5,219,355, discloses aballoon device for implanting an aortic interluminal prosthesis torepair aneurysms. In the patent, a graft prothesis is disposed upon acatheter having two balloons mounted thereon. The prosthesis is mountedon the catheter and stents are mounted upon the balloons. The assemblyof the graft, the two balloons and the stents are introduced into theaneurysm by catheterization. The balloons are inflated to implant theprosthesis within the aneurysm and affix the stents against the arterywalls, thereby to repair the aneurysm. The balloons are deflated and thecatheter is withdrawn.

SUMMARY OF THE INVENTION

[0006] According to the present invention I have discovered aninterluminal prothesis especially useful for intraluminal repair ofaneurysms. The prothesis includes a generally tubular flexible graft ofconventional prosthetic graft material having a proximal open end and atleast one leg with a distal open end and preferably two legs with twodistal open ends. Preferably, a first stent is disposed within andattached to the proximal open end. The first stent emerges from theproximal open end and is adapted to be attached to the aortaintraluminally. A hem terminating in the distal open end of the graft isinverted within the leg. The hem is arranged as a cuff within the leg. Asecond stent having a proximal and a distal end can be attached to theinterior of the distal end of the cuff so upon withdrawing the secondstent from the cuff, the cuff will unfold and follow the stent forimplantation of the graft. In a preferred embodiment the graft isbifurcated at one end to form two legs, each terminating in distal openends. Each leg is attached to one of the iliac arteries. In thepreferred embodiment also, the hem is inverted a second time to form asecond cuff within the first cuff. The stent extends outwardly from thedistal open end of the second cuff. Many of the stents are devices whichare deformed by increasing the diameter until they engage a wall of abody conduit and are anchored thereto. Alternatively they may beintegrally knitted into the graft or they may be polymeric impregnationsof the graft which harden upon heating to enable the hardenedimpregnation to engage the body conduit.

[0007] To dispose the graft within the aorta a conventional guidewire isthreaded through the iliac artery into the aorta using conventionaltechniques. A delivery catheter is then threaded over the guidewireuntil it reaches the desired location within the aorta. A graft havingat least two open ends is disposed on the delivery catheter. Each openend of the graft can have a stent disposed therein. The portion of thegraft that is adapted to be attached to the aorta has the stentextending outwardly from its open end so that the graft may be attachedto the aorta. In the case of a bifurcated graft in which two legs of thegraft are to be attached to the two iliac arteries branching from theaorta, one of the legs can have a stent extending outwardly from itsopen end. The other leg of the graft is disposed inside the graft leg inthe form of a cuff which is inverted into itself at the open end. Astent can be attached to the cuff. A balloon catheter is disposed nearthe end of the inverted leg. The inside of the inverted leg is engagedby the balloon and is withdrawn through the other iliac artery. Whenappropriately positioned within the iliac artery, the stent is expandedto engage the artery and set it. The balloon and then the guidewire isthen withdrawn from the artery and the procedure is completed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is a side elevational view partially in cross section ofone embodiment of a bifurcated aortic implant adapted to be disposedwithin an aneurysm formed in the aorta and connected to each iliacartery.

[0009]FIG. 2 is a side elevational view, partially in cross-section,illustrating another embodiment of an aortic implant.

[0010] FIGS. 3 to 10 are a series of views showing a stage-wiseprogression for performing a procedure to implant a graft within anaortic aneurysm.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Referring now to FIG. 1, an arterial interluminal prosthesis 20for repairing aneurysms is shown, partially in cross section. The graftor prosthesis, when implanted, has a generally circular cross-sectionalconfiguration. It may be made from a variety of materials provided theyhave requisite strength characteristics to be utilized an aortic graftas well as have requisite compatibility with the human body so that theimplant material will not be rejected. Examples of such material areDacron® and other polyester materials, Teflon®(polytetrafluoroethylene), Teflon® coated with Dacron® material andporous polyethylene urethane. The material can be knitted or woven. Thegraft can also be made of extruded polymeric materials, all of which arewell known to the art as graft materials.

[0012] The graft 20 has a proximal open end 30 and two distal open ends31 and 32. The distal open ends are disposed on legs 23 and 24 whichbifurcate from the graft 20. Each leg preferably is the same lengthinitially, although with some procedures it may be preferable to makethe legs axially stretchable to provide for adjustments in length whichmay be needed during implantation. The distal open end 31 of the leg 24is at the end of a hem 33 which extends from the edge of the inward foldof the leg 24 to the distal open end 31. The length of the leg 24 is notcritical so long as it is adequate to be grasped by a catheter andintraluminally drawn into the iliac artery. A first inversion of the hem33 forms a first cuff 34. In the preferred embodiment the hem 33 isinverted a second time to form a second cuff 35 which opens away fromthe proximal open end 30. Preferably the leg 24 (or both the legs 24 and23) are truncated or tapered with the narrowest diameter being at thedistal open ends to enable the hem to be more easily folded within theleg and form a cuff(s).

[0013] A stent (not shown) is disposed within the distal open end 31 ofgraft 20. The stent emerges from the distal open end 31 to enable it tobe attached to the iliac artery. Another stent (not shown) is disposedwithin the leg 23 at its distal open end 32. A third stent (not shown)is disposed in the proximal open end 30 to attach to the thoracicartery.

[0014] Several types of stents can be used. Common stents are plexusesof wires that can be expanded with internal force, such as provided by aballoon, to engage an artery wall. Other stents having applicabilityinclude polymeric expandable structural members and polymericcompositions at the end of the leg which harden when expanded andactivated by heat. A stent can alternatively be constructed as a liningwithin a graft and extending from one end of the graft to the other toprovide for both fastening of the graft to an artery and its structuralstability.

[0015] Referring now to FIG. 2, a graft 40 is shown partially incross-section. In this embodiment the graft 40 is tubular-shaped anddoes not have two legs as is disclosed in the previous embodiment. Thegraft 40 has a proximal open end 41 in which a stent 42 is disposed. Thegraft 40 further has a distal open end 43 disposed at the end of a hem44. The hem 44 is inverted within the graft 40 to form a first cuff 45and in the preferred embodiment is inverted a second time to form asecond cuff 46. The second cuff 46 is especially beneficial because itenables the hem 33 to be withdrawn from the leg 24 easily. When a stentis inserted within the distal open end 43 it can engage the distal openend 43 to draw the hem 44 outwardly and cause the cuff 45 to unfold andthen cause the cuff 46 to unfold also. In this embodiment, as with theembodiment illustrated in FIG. 1, the graft 40 can be truncated ortapered toward the distal open end to provide for easy inversion of thehem 44 into the graft 40. In the preferred embodiment, the hem istruncated into two progressively narrower diameters or tapered with thedistal open end 43 having the smallest diameter.

[0016] FIGS. 3 to 10 show a portion of the abdominal aortic artery to betreated connected in its upper part with thoracic artery 1 from whichrenal arteries 2 depart. The abdominal aorta presents an aneurysm 5which goes almost to the thoracic aorta 1. The thoracic aorta 1bifurcates at 13 into two iliac arteries 11 and 12.

[0017] A conventional guidewire 3 is conventionally threaded into theright iliac artery 11 into the abdominal aorta through the aneurysm 5until it reaches the thoracic aorta 1, as shown in FIG. 3.

[0018] Referring to FIG. 4, implantation of the graft illustrated inFIG. 1 is shown. A delivery catheter covered by a sleeve 14 is slippedover the guidewire 10 until its distal end is located above the aneurysm5. The delivery catheter includes a hollow center shaft (not shown)covered by the graft as shown in FIG. 1, the graft being tightly wrappedaround the delivery catheter, as is conventional. The assembly of thedelivery catheter would be the same for the embodiment shown in FIG. 2.If stents are delivered with the graft, they are collapsed, as isconventional also. The graft and stents are covered by the sleeve 14, asis conventional also. After delivery of the graft, it is positioned sothat its proximal open end 30 is above the aneurysm 5. The sleeve 14 iswithdrawn through the iliac artery 11 to leave the graft and stentuncovered. In the embodiment shown, especially in FIG. 5, as the sleeve14 is withdrawn through the artery 11, stent 21 will automaticallyenlarge to engage the aorta wall 1 and as the sleeve 14 is furtherwithdrawn, stent 22 enlarges and engages the interior of artery 11 toanchor the graft 20 in place.

[0019] Referring to FIG. 5, the graft 20 is shown expanded and deployedbetween the thoracic artery 1 and the right iliac artery 11. Stent 21has enlarged (or been enlarged) to engage the interior wall of thethoracic artery 1 and hold the graft 20 in place. The second stent 22 isshown engaging the right iliac artery 11 to hold left leg 23 in place.With the delivery mechanism illustrated in FIG. 4, the graft 20 has beendelivered with the stents 21 and 22 in place within graft 20. The rightleg 24 of the graft has been inverted within the graft 20 during thedelivery. When the stents are deployed, the right leg 24 will remaininside of the graft 20. Following deployment of the graft 20, theguidewire 10 and center shaft 25 (upon which the graft 20 was mountedwhen the device was deployed within the artery) is withdrawn through theright iliac artery 11.

[0020] As shown in FIG. 6, a catheter 26 is inserted into the left iliacartery 12 and directed into right leg 24 that is inverted in the graft20. One of the more suitable means for engaging the leg 24 is a cathetercarrying a balloon 37 with a stent mounted upon it (if the leg 24 wasnot implanted with a stent already in place) Enlargement of the balloon37 will enlarge the stent sufficiently to enable the stent to grasp theinside of the leg 24 and withdraw it through itself. Alternatively, acatheter with a stent mounted on it can be inserted into the leg 24after it has been drawn into the left iliac artery 12. Another mechanismto withdraw the leg is to insert a hook which will engage the invertedleg. The stent can be enlarged as described above.

[0021] As shown in FIG. 7, the catheter 26 that was inserted into theleft iliac artery 12 to engage the distal open end of the leg 24 isbeing withdrawn from within the graft 20 by drawing catheter 26 throughthe artery 12. The distal open end and the inverted leg 24 will followit. When the inverted leg 24 is fully withdrawn, one of severaltechniques can be used to implant the stent. In one technique, the stentis deployed upon a balloon catheter and inflation of the balloon (whenthe stent is in a correct position in the left iliac artery 12) willcause the stent to be seated. Another approach involves a stent disposedwithin the leg 24 while it is inverted within the graft 20. In thisapproach, when the leg 24 is drawn from the graft 20 the stent willemerge and enlarge automatically as the leg 24 is drawn out. Moreoverthe stent can be a polymeric impregnation of the leg, as mentionedabove. Expansion of the leg 24 against the artery and heating willstiffen the leg 24 to implant the prosthesis.

[0022] In FIG. 8 the balloon catheter is shown enlarging the stent to itin the iliac artery 12. FIG. 9 shows the balloon catheter being movedfrom the position within the stent 28 just immediately prior towithdrawal of the catheter 26 from the iliac artery. The balloon can bedeflated to allow for easy withdrawal of the catheter from the stent andthrough the artery.

[0023]FIG. 10 shows the graft 20 implanted between the two iliacarteries 11 and 12 and the thoracic aorta 1. A stent 22 anchors the leftleg 23 of the graft 20 to the right iliac artery 11 and a stent 28anchors the right leg 24 to the left iliac artery 12. The aneurysm 5surrounds the graft but does not receive blood into it. Drainage of theaneurysm can be accomplished percutaneously or otherwise, as isconventional.

[0024] The graft depicted in FIG. 2 of the drawings having only onedistal open end can be deployed and implanted similarly as theembodiment shown in FIG. 1, except the procedure is less complicated inthat the procedure requires entering through only one of the iliacarteries.

[0025] While it is apparent that changes and modifications can be madewithin the spirit and scope of the present invention, it is myintention, however, only to be limited by the appended claims.

As my invention I claim:
 1. An intraluminal prosthesis for intraluminalrepair of body conduits, said prosthesis comprising: a generallytubular, flexible graft having a proximal open end and at least onedistal open end terminating in a hem, said hem being inverted withinsaid graft such that said hem is disposed as a cuff within said graft,said hem being arranged so that upon withdrawing said distal open endfrom inside said cuff, said cuff will unfold and follow said distal openend to expose it to receive a stent for attachment to said body conduitfor intraluminal implantation of said graft.
 2. An intraluminalprosthesis for intraluminal repair of body conduits, said prosthesiscomprising: a generally tubular, flexible graft having a proximal openend and at least one distal open end terminating in a hem; a stentdisposed within said proximal open end and means for attaching saidstent to said graft, said stent emerging from said proximal open end andadapted to be attached to said body conduit, said hem being invertedwithin said graft such that said hem is disposed as a cuff within saidgraft, said hem being arranged so that upon withdrawing said distal openend from inside said cuff, said cuff will unfold and follow said distalopen end to expose it to receive another stent for attachment to saidbody conduit for intraluminal implantation of said graft.
 3. Theprosthesis according to claim 2 wherein said hem is folded a second timewithin said cuff to form a second cuff within said graft
 4. Theprosthesis according to claim 2 wherein said stents are formed of aself-expanding plexus of wires adapted to expand from a first narrowdiameter to a second diameter or of a plexus of wires that is expandableby the application of interior force to a larger internal diameter toengage said body conduit.
 5. An arterial intraluminal prosthesis forrepairing aneurysms comprising: a generally tubular, flexible grafthaving a proximal open end and at least one distal open end terminatingin a hem; a first stent disposed within and attached to said proximalopen end and emerging therefrom and adapted to be attached to theartery; said hem being inverted within said tubular graft such that saidhem is arranged as a first cuff within said graft, said hem beingfurther inverted within said first cuff to form a second cuff, saidsecond cuff terminating in said distal open end, said distal open endbeing arranged such that upon withdrawing said distal open end, the hemand then the cuffs will unfold and follow said distal open end forarterial implantation of said graft.
 6. An arterial intraluminalprosthesis for repairing aortic aneurysms and connecting to iliacarteries, said prosthesis comprising: a generally tubular, flexiblegraft having a proximal open end and two distal open ends, each of saiddistal open ends being disposed on legs which bifurcate from said graft;a first stent disposed within and attached to said proximal open end andemerging therefrom and adapted to be attached to the aorta; a secondstent disposed within and attached to a distal open end of one of saidlegs and emerging therefrom and adapted to be attached to the iliacartery; a hem disposed on the other leg of said graft, said legterminating in the other of the distal open ends, said hem beinginverted within said other leg to form a cuff within said graft, saidcuff being arranged to unfold and follow said distal open end forimplantation of said graft in the other iliac artery.
 7. The prosthesisaccording to claim 6 wherein said hem is folded a second time withinsaid cuff to form a second cuff within said leg.
 8. The prosthesisaccording to claim 6 wherein said stents are formed of a self-expandingplexus of wires adapted to expand from a first narrow diameter to asecond diameter or of a plexus of wires that is expandable by theapplication of interior force to a larger internal diameter to engagesaid body conduit.
 9. A method of intraluminally implanting a graftwithin a body lumen, said method comprising: intraluminally inserting ina body conduit a generally tubular, flexible graft with a proximal openend and at least one distal open end and a first stent disposed withinand attached to said proximal open end and emerging therefrom andwherein said distal open end of said graft is inverted within saidtubular graft such that said distal end is arranged as a cuff withinsaid graft; locating said graft in a predetermined position within saidbody lumen; expanding said first stent and attaching it to said bodylumen; intraluminally engaging said cuff and withdrawing said distalopen end from inside said cuff thereby unfolding said cuff from withinsaid distal end of said graft; enlarging the internal diameter of asecond stent disposed within said distal open end and attaching saidsecond stent to said body lumen thereby implanting said graft.
 10. Themethod according to claim 9 wherein said second stent is disposed withinsaid cuff and emerges from said distal open end and said cuff iswithdrawn by engaging said second stent.
 11. A method of intraluminallyimplanting a graft within an aorta, said method comprising:intraluminally inserting in an iliac artery branching from said aorta agenerally tubular, flexible graft with a proximal open end and with atleast one distal open end and with a first stent disposed within andattached to said proximal open end and emerging therefrom and whereinsaid distal open end of said graft includes a hem, said hem beinginverted within said tubular graft such that said hem is arranged as acuff within said graft; locating the proximal open end of said graft ina predetermined position within said aorta; expanding said first stentand attaching it to said aorta; intraluminally engaging said hem andwithdrawing it from inside said cuff and drawing it into an iliac arterythereby unfolding said cuff from within said distal end of said graft;expanding a second stent and attaching it to the iliac artery into whichit was withdrawn thereby implanting said graft.
 12. A method ofintraluminally implanting a graft within an aorta, said methodcomprising: intraluminally inserting into one of two iliac arterybranching from said aorta a generally tubular, flexible graft with aproximal open end and with two distal open ends on two legs branchingfrom said graft and with a first stent disposed within said proximalopen end and emerging therefrom and wherein there is another stentdisposed on a hem of one of said legs of said graft and emergingtherefrom and wherein a hem on the other of said legs is inverted withinsaid other leg to form a cuff within said other leg; locating theproximal open end of said graft in a predetermined position within saidaorta; expanding said first stent and attaching it to said aorta;intraluminally engaging said another stent and expanding it to attach itto the iliac artery through which said graft was inserted;intraluminally engaging said cuff through said other iliac artery andwithdrawing it from inside said leg and drawing it into said other iliacartery thereby unfolding said cuff from within said distal end of saidgraft; expanding another stent and attaching it to said other iliacartery thereby implanting said graft.
 13. The method according to claim12 wherein said hem on the other of said legs is folded a second timewithin said cuff to form a second cuff within said distal open end. 14.The method according to claim 12 wherein said stents are formed of aself-expanding plexus of wires adapted to expand from a first narrowdiameter to a second diameter or of a plexus of wires that is expandableby the application of interior force to a larger internal diameter toengage said body conduit.